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Cellulosic bioethanol is a promising renewable and substitute source of energy. To make the bioconversion of LCB to fuels cost effective and energy efficient, it is essential to reduce the recalcitrance of LCB and unravel the process of biomass deconstruction. Present study employed sequential dilute acid-alkali pretreatment of sugarcane bagasse (SCB) for enhancing its bioconversion to ethanol. Box-Behnken and D-optimal designs were used to optimise the process of dilute acid and alkali pretreatments sequentially, resulting in an optimum concentration of 3% (v/v) and 5% (w/v) for H2SO4 and NaOH with solid SCB loadings of 18 and 15% (w/w), respectively, for 30 min at 121 °C. The effectiveness of sequential pretreatment was supported by increased cellulose content (83%), drop in hemicellulose, enhanced delignification and 60% enzymatic hydrolysis of SCB by in-house Trichoderma reesei cellulases at enzyme dose of 20 FPU/g. The favourable multi-length scale ultrastructural changes in SCB induced by pretreatment were confirmed by FT-IR, SEM, EDX, TGA, XRD and small angle neutron scattering (SANS). SANS revealed increase in small pore radii from 11.1 to 18.5 A, indicating improved biomass porosity after sequential pretreatment. Thus, sequential pretreatment of LCB effectively reduced the recalcitrance and could be more useful in lignocellulosic biorefinery applications.

Graphene possesses a large surface area and offers high loading capacity for aromatic compounds. However, the load is quickly released in the absence of rate limiting diffusion barrier. In this study, we have explored the electrostatic interaction between polyanionic hyaluronic acid (HA) and cationized reduced graphene oxide (rGO) as a means to develop a reinforced hydrogel matrix. We tested if; (i) degradation kinetics of HA matrix can be modulated in the presence of cationized nanosheets, and (ii) reinforced hydrogel can offer controlled release of paclitaxel (PLX) stacked over the sheets. Successful synthesis, cationization and drug loading on graphene sheets were demonstrated using Raman and FT-IR spectroscopy. Reinforcement was confirmed through electron microscopy, neutron scattering and texture profile analyses. While incorporation of sheets enhanced the resistance of HA hydrogel against enzymatic digestion, a significant improvement in the biocompatibility of cationized rGO was obtained through this association. Reinforced gel offered sustained release of PLX up to 104 h which can further be extended by tuning its architecture.

The nanoparticles in solution represent a model system, where the well-established colloidal theories such as the Debye–Huckel theory and/or Derjaguin–Landau–Verwey–Overbeek theory can be implemented to predict the nanoparticle phase behavior. Recently, reentrant phase transitions in a wide range of colloids (e.g., inorganic and organic nanoparticles, polymers, and biomolecules) have been observed, which are not consistent with these theories. The colloids in the reentrant phase behavior undergo a phase change and return back to the original phase with respect to a specific physiochemical parameter (e.g., ionic strength, concentration of different additives, temperature, and so on). The nanoparticle–polymer/multivalent ion systems, demonstrating such phase transition and the corresponding phase behavior in terms of interparticle interactions, have been probed by small-angle scattering. It has been shown how the tuning in interparticle interactions using external parameters can lead to reentrant phase behavior and use the nanoparticle aggregation for building nanohybrids. The deviations of the present observations from those of the standard colloidal theories and the anticipated challenges are also discussed.

Polysorbate 80 is one of the most widely used solubilizing agents in food, cosmetic and pharmaceutical industries. Influences of different classes of solubilizates and additives on its self-assembly characteristics are however, not sufficiently understood yet. In this manuscript, we show how common water structure making salt NaCl, and lipophilic phytochemicals like curcumin and lavender oil help in modulating the structure of Polysorbate 80 micelles in aqueous medium. Our DLS, SANS and rheological studies show that NaCl induces sphere-to-rod growth of polysorbate 80 micelles at the room temperature. Micellar solubilizations of the phytochemicals, which were found to be facilitated with increase in temperature, induce only a marginal growth of the micelles up to the highest level of solubilization. Their presence however, helps in modulating the NaCl induced micellar growth behavior in the tween 80 solutions leading to observation of micelle-to-vesicle structural transition at 2% lavender oil concentration. The phytochemical solubilized micellar solutions could be converted to alginate based hydrogel beads and patches that can freely release micellar phytochemical in aqueous medium. Our results shed light on possible ways of modulating the solubilization behavior, self-assembly characteristics and rheological properties of aqueous system of polysorbate 80, which could be important for their applications.

Strategies (composition, morphology and spacer nature variations) are reported for aqueous solubility enhancement of hydrophobic material. Critical micelle concentration (cmc) of mixed oppositely charged gemini surfactants has been studied conductometrically. Phosphoric acid, P, P′-1,4-butanedieyl, P, P′ didodecylester, disodium salt is used as an anionic component while cationic geminis, with different spacers (polymethylene, ethylenediamine, isosorbide, and ethylene glycol), are used as another component. Based on micellar interaction parameter (βm), both synergistic and antagonistic interactions are observed. Zeta-potential shows variation in charge (or charge reversal) of the mixed aggregate. Small angle neutron scattering, dynamic light scattering and transmission electron microscopy show spacer nature dependent formation of micelles/vesicles. Molar solubilization ratio, of polycyclic aromatic hydrocarbon (PAH), suggests higher solubilization in vesicles. Solubilization depends on the vesicle electrostatics and bi-layer thickness. Potential key factors of the process seem bi-layer polarity and interaction with individual PAHs. Approach might be employed to enhance aqueous solubility/bioavailability of other hydrophobic materials such as drugs, dyes or pesticides.

Linear water-soluble stimuli-responsive double hydrophilic block copolymers, poly(N-isopropylacrylamide)-block-poly(acrylic acid) [abbreviated as PNIPAM-b-PAA (degree of polymerization (DP) of PNIPAM = 149 and DP of PAA = 46 or 85)] were synthesized using reversible addition−fragmentation chain transfer (RAFT) polymerization technique and characterized by gel-permeation chromatography (GPC) and nuclear magnetic resonance (1H NMR) spectroscopy. Turbidimetry, spectral, and scattering studies showed that block copolymers remain as molecularly dissolve in water below the lower critical solution temperature (LCST) of PNIPAM block (~32 °C). Turbidimetry results confirm the formation of aggregates with PNIPAM core and PAA as a shell in the presence of NaCl, CaCl2 and at temperatures above the LCST of PNIPAM. The cloud point temperature (TC) of both block copolymers increases with an increase in DP of PAA in neutral and basic pH and decreases at low pH. Small angle neutron scattering (SANS) data confirmed the formation of worm- or thread-like micelles in the presence of a cationic surfactant dodecyltrimethylammonium bromide (DTAB).

Silica nanomaterials modified with monomolecular C18-alkyl silane or oligomeric dimethylsiloxane units were loaded in-situ during the formation of PDMS membrane. The small-angle neutron scattering (SANS) study was performed to probe structural compatibility between the modified silica and PDMS. The Ornstein-Zernike (OZ) and Debye-Anderson-Brumberger (DAB) models were excellently fit to the SANS data describing nanoscale structure morphology in terms of correlation length scales of the soft and hard segmental units. The polymeric chain was stretched or contracted depending upon the type and amount of silica incorporation. This indicated limiting amount of silica incorporation in the PDMS membrane structure depending upon structural compatibility between the silica and PDMS. The C18-alkyl silylated silica was found to be the best compatible with the membrane structure. The membrane with 30% (w/w) C18-alkyl silylated -silica loading exhibited the best performance in pervaporation separation of alcohol/water.

The present study deals with the self-assembly of a pure graft copolymer: Soluplus® and a non-ionic surfactant: Solutol® HS15 and focuses on their clouding behaviour [expressed as cloud point (CP)] in the presence of different additives viz. inorganic salts (NaF, NaCl, NaBr, NaI, NaNO3, KCl, KBr, KI), bile salts (sodium cholate-NaC, sodium taurocholate-NaTC, sodium deoxycholate-NaDC), denaturants (urea, methylurea, dimethylurea), amino acids (alanine, glycine, lysine, valine, cysteine hydrochloride), sugars (glucose, fructose, mannitol, sucrose, maltose, lactose), cationic surfactants (cetyltrimethylammonium bromide-CTAB, tetradecyltrimethylammonium bromide-TTAB, dodecyltrimethylammonium bromide-DTAB) and alcohols (methanol, ethanol, propanol, 1-butanol, ethanediol, 1,3-propanediol, 1,4-butanediol). The aqueous solutions of these amphiphiles show a complex phase behaviour and have revealed the occurrences of spherical micelles using dynamic light scattering (DLS) and small-angle neutron scattering (SANS) techniques. Herein, we report the variation of amphiphilic CP in the presence of different kinds of additives that show the influence of the water structure and its hydrophobicity, making this study important for pharmaceutical/ biomedical applications.

D -alpha-tocopheryl polyethylene glycol 1000 succinate (TPGS) is a nonionic surfactant with low critical micelle concentration. It usually forms spherical core-shell micelles in aqueous media. In this work, we show that these spherical micelles transform to ellipsoid and cylindrical structures upon the incorporation of commonly available monosaccharides, Glucose (GLC), mannose (MAN) and galactose (GAL). The aggregates have been characterized by dynamic light scattering (DLS), small angle neutron scattering (SANS) and nuclear magnetic resonance (NMR) spectroscopy. Our analysis is focused to discuss (a) the effect of sugar concentration, and (b) comparative ability of sugars in triggering structural transitions. It is shown that the transitions and micelle growth arose from the sugar-driven dehydration of head group region. With their higher affinity, sugar molecules approached the shell region and triggered expulsion of water molecules. Although the pattern of transition (micelle to ellipsoid to cylinder) remained common for each sugar, it began at lower concentration of GLC and GAL. NMR experiments showed structural reorganizations in TPGS molecule in the presence of sugar. The outcomes of our study can be applied to tune the viscosity of nonionic surfactant-based long-standing pharmaceutical dispersions.

This work reveals the role of sodium dodecylsulphate (SDS, anionic surfactant) in altering the phase behaviour and aggregation characteristics of five very hydrophobic polyethylene oxide-polypropylene oxide-polyethylene oxide (PEO-PPO-PEO) triblock copolymers containing 10% PEO but with different molecular weight. These copolymers are molecularly dissolved in water at ≤15–20 °C and exist as unstable vesicular structure at temperature close to cloud point (CP) >20 °C. SDS enhanced the aqueous solubility and CP of copolymers in water; progressive addition of SDS triggered the transformation of unstable vesicles into spherical mixed micelles. A correlation between the molecular orbital energy levels of Pluronics® and SDS is well comprehended using computational simulation approach where the perception of SDS stabilized Pluronics® micelles is predicted and correlated with optimized parameters. The size/ shape of copolymer-surfactant mixed nanoscale aggregates was evaluated using dynamic light scattering (DLS) and small-angle neutron scattering (SANS). The scattering studies showed the presence of spherical mixed aggregates, whose size expanded with increase in hydrophobicity of Pluronics®. In high SDS concentration regime, SANS analysis uncovered the diminishing size of vesicles into spherical mixed aggregates. The nanoscale Pluronics®-SDS mixed micelles remained stable in water where this investigation discloses the conceivable ability of orange-OT solubilization using UV–vis spectroscopy.

The interaction of cinnamic acid (CA) and its analogues viz. p-coumaric acid (PCA) and caffeic acid (CFA) with core-shell micelles of a moderately hydrophobic Pluronic® P123 has been investigated using cloud point (CP), viscosity, dynamic light scattering (DLS), small-angle neutron scattering (SANS) and steady-state fluorescence measurements. These solubilizates alter micellar behaviour of copolymer solution dependant on their hydrophobicity. P123 micelles exhibit time-dependent restructuring and responsive growth processes at different rates, depending on pH and in the presence of additives. Thus, restructuring and growth of P123 micelles can be easily tuned up to a substantial extent just by changing the concentration of the additives and the pH of the solution. Considering the medical applications of cinnamic acid and its analogues and considering use of Pluronics® in drug delivery systems, the present study can provide important insight of the possible time-dependant delivery mechanism of drugs.

Small angle neutron scattering study reveals that below the isoelectric point of the globular protein lysozyme and in the presence of different divalent (Mg2+, Ca2+ and Ba2+) and monovalent (Na+) ions, the long-range repulsive and the short-range attractive interactions decreases and increases respectively with the increase of salt concentration. In addition with these short- and long-range interactions, fractal aggregates also form even in pure lysozyme solution by a very small amount (≈0.5%). Protein-protein interactions are mostly dominated by the fractal structure factor only for Na+ and Mg2+ ions at higher salt concentrations as more aggregates are formed.

Herein, alkyl chain dependent self-assembly of choline carboxylate ionic liquids (ILs) and their effect on micellar characteristics of a star block copolymer (Tetronic®T1304) are reported. The ILs showed good aqueous solubility (low Kraft point) and formed spherical micelles. Small angle neutron scattering (SANS) analyses revealed a reduction in the critical micelle concentration (CMC) and elevation in the aggregation number (Nagg) upon increasing alkyl chain length of ILs. More importantly, ILs demonstrated good biocompatibility in murine erythrocytes and A549 cells, irrespective of the chain length. Furthermore, the effect of IL addition on micellar behaviour of T1304 was examined through thermal and scattering studies. We observed alkyl chain dependent increase in the cloud point (CP), critical micellization temperature (CMT), micelle size (Rh, Rc, Rhs) and Nagg. In association with T1304, long chain ILs (n = C12–C18) formed charged mixed micelles with a lower Nagg which showed enhanced solubilization of quercetin, a hydrophobic drug. Mixed micelles, composed with such biocompatible ILs, can further be tuned to explore their drug delivery applications.

Micellar aggregates formed in aqueous solution of Gemini surfactant: N, N′-didodecyl-N,N, N′,N′ tetramethyl-N,N′-ethanediyldiammonium dibromide (12-2-12), in presence of organic additive: Phenyl Propiolic acid (PPA), has been systematically characterized by rheology, 1H-NMR, fluorescence spectroscopy, dynamic light scattering (DLS), small angle neutron scattering (SANS), transmission electron microscopy (TEM), and contact angle (CA) techniques as a function of temperature. 12-2-12 undergo micellar transition from elongated ellipsoidal micelles to unilamellar vesicles (ULV) upon addition of varying amount of PPA as a function of temperature which was inferred by scattering and microscopy results. The quantification of the geometrical parameters of 12-2-12 micelles was achieved by a complete fit of the obtained SANS data using prolate ellipsoidal form factor and the structure factor model thereby confirming the presence of elongated ellipsoidal micelles and ULV. Variation of the viscosity with the shear rate for the ratio 50 mM 12-2-12: 10 mM PPA exhibited the typical viscoelastic characteristics which are further investigated by dynamic rheological measurements. 1H-NMR study indicated the substantial change in the chemical shifts of the protons for 12-2-12 with the addition of PPA, thereby inferring the significant interaction between the two components leading to such micellar transition. Furthermore, DLS and Fluorescence study suggested the formation, aggregation and collapse procedure of the network structures of the 12-2-12+PPA system, which either resulted in increase or decrease of viscosity as a function of PPA concentration and temperature. Such observation is evidently complimented by TEM findings and CA study. The structural dynamics of these aggregates corresponding to the interaction between them are well correlated with quantum simulation approach using Density Functional Theory (DFT)/B3LYP with the basis set 3-21G method.

Development of drug delivery systems, not the drug discovery, has become more cynosures towards the efficacy of drug against the target cells. Modified hybrid cationic vesicles (HCV) were formulated using soylecithin (SLC), ion pair amphiphile (IPA, hexadecyltrimethylammonium-dodecylsulfate, HTMA + -DS - ), bi-tail cationic surfactant dialkyldimethylammonium bromides (DXDABs, bis-C12 to C18) and cholesterol. Piroxicam (Px), a conventional non steroidal anti inflamatory drug (NSAID), with potent yet unexplored anticancer activity,was encapsulated in the hybrid vesicles. Dual impact of DXDABs and Px on SLC/IPA were scrutinized in the form of monolayer, bilayer and solid supported bilayer. Favourable hydrophobic inteaction between SLC/IPA and dihexadecyldimethylammonium bromide (DHDAB) as well as the intercalation of Px molecules between the amphiphiles were noticed through the surface pressure area measuremnts. Vesicles without and with Px were fairly monodisperse with positive zeta potential (Z. P.) and considerably stable upto two months. Size of the vesicles enhanced with Px incorporation. Vesicles maintain spherical morphology as revealed from the electronic microscopic studies. Differential scanning calaorimetry and FTIR studies confirm the location of Px membrane palisade that enhances the extent of hydration by increasing the proportion of H-bonding. Bilayer thickness and the spacing between two adjecent lamellar phase were investigated by combined small angle neutron scattering and small angle X-ray scattering. Atomic force microscopic studies confirm the Px induced fluidization of membrane bilayer. The entrapment efficiency of vesicles to host Px depends on the amount of IPA present in the bilayer. Px hosted cationic vesicles showed less than 2% hemolysis. The drug reigned supreme over human neuroblastoma cell line (SH-SY 5Y) when encapsulated inside the membrane and was non toxic to normal human blood cell lymphocyte (PBMC) as revealed from cytotoxicity assay.

The present study was aimed to examine the interaction of two bile salts viz. sodium cholate (NaC) and sodium deoxycholate (NaDC) with three ethylene polyoxide-polypropylene polyoxide (PEO-PPO-PEO) triblock copolymers with similar PPO but varying PEO micelles with a focus on the effect of pH on mixed micelles. Mixed micelles of moderately hydrophobic Pluronic® P123 were examined in the presence of two bile salts and compared with those from very hydrophobic L121 and very hydrophilic F127. Both the bile salts increase the cloud point (CP) of copolymer solution and decreased apparent micelle hydrodynamic diameter (Dh). SANS study revealed that P123 forms small spherical micelles showing a decrease in size on progressive addition of bile salts. The negatively charged mixed micelles contained fewer P123 molecules but progressively rich in bile salt. NaDC being more hydrophobic displays more pronounced effect than NaC. Interestingly, NaC shows micellar growth in acidic media which has been attributed to the formation of bile acids by protonation of carboxylate ion and subsequent solubilization. In contrast, NaDC showed phase separation at higher concentration. Nuclear Overhauser effect spectroscopy (NOESY) experiments provided information on interaction and location of bile salts in micelles. Results are discussed in terms of hydrophobicity of bile salts and Pluronics® and the site of bile salt in polymer micelles. Proposed molecular interactions are useful to understand more about bile salts which play important role in physiological processes.

Hydrocarbon permselective membranes comprising of Poly (dimethylsiloxane) (PDMS) with Zeolitic Imidazole Framework (ZIF)-8 nanocrystals have been explored. ZIF-8—PDMS membranes of different ZIF-8 loadings were prepared in different solvents. The polymer chain conformations were observed by Ornstein-Zernike model fit to their small-angle neutron scattering profiles. The chain conformations were found to be varied for the membranes with different ZIF-8 loadings. The Debye-Anderson-Brumberger model showed larger scattering domains for the ZIF-8—PDMS membranes prepared in toluene than the membranes prepared in n-heptane. The membrane (toluene) of optimal ZIF-8 loading exhibited ∼60% increment of hydrocarbon permeability but ∼2% increment of N2 permeability as against ∼300% increment of hydrocarbon permeability and >30% of N2 permeability for the membrane (n-heptane) of the similar ZIF-8 loading. This different phenomenon of hydrocarbon permeability enhancement for the membranes with the ZIF-8 loading can be attributed to their different membrane nanostructures.

Various synthesis approaches of gel or colloidal solution system have been applied to prepare LTA zeolite with Si/Al ratio >1 to improve their thermal stability for applications in catalysis and separation process. While a cooperative templating of the mixed templates as structure-directing agents was typical for the synthesis from the gel system, the templating process of colloidal system may be varied depending on their synthesis composition systems. Using SANS technique, we probe nucleation of Si-rich LTA (Si/Al ratio > 1) nanocrystals from a colloidal solution synthesis system comprising of Ludox AS-40, Aluminium isopropoxide, TMAOH, NaOH and water. The SANS measurements at contrast match condition were also performed to contrast out of silica for examining the scattering signatures of the species other than the silica. The study brings new insights to the formation of industrially important Si-rich LTA nanocrystals of sizes ca. 50–100 nm. The relative change in the nucleation behaviour of the typical LTA (Si/Al ratio = 1) as observed by the SANS was also discussed. Our findings showed a dual heterogeneous nucleation of the LTA from the colloidal solution by forming -Si-O-Al- (aluminosilicate) nanomaterials in the solution as well as on the solid surface. The Si-rich LTA formation was predominantly originated from the nucleation in the liquid phase whereas the heterogeneous nucleation of the typical LTA mainly occurred on the exterior solid surface of the silica precursor. Thus, the different types of nanoscale structures nucleated from the colloidal syntheses should lead into the formation of LTA nanocrystals of different properties.

The phase behaviour and aggregation characteristics of aqueous solution of Triton X-100 in the presence of several 1-alkyl-3-methylimidazolium salts, [Cnmim+]X− and 1-alkylpyridinium salts [CnPy+]X−, where n is the alkyl chain length (4,6,8.10) and X− is the anion CF3SO3− and BF4− has been explored. The effect of nonpolar alkyl chain length, cation and anion of these ionic liquids was investigated from cloud point (CP), dynamic light scattering (DLS) and small angle neutron scattering (SANS). ILs with longer alkyl chain on cation drastically increased CP and decreased micelle size. The size, hydrophobicity and polarity of anions also showed marked effect on solution behavior of Triton X-100. The results indicate opposite effect on CP and hydrodynamic diameter (Dh) on addition of ionic salts. SANS results demonstrate that added ILs modulated the size of TX-100 micelle, which is further discussed in terms of penetration of cation and anion into TX-100 micelle depending on the nature of alkyl chain attached to the cation/anion and varying size, hydrophobicity, surface activity of anion.

Small angle neutron scattering study reveals that at pD ≈ 7.0, above the isoelectric point of the globular protein Bovine Serum Albumin (BSA), in the presence of different divalent ions (Mg2+, Ca2+, Sr2+ and Ba2+), the short-range attractive interaction remains nearly constant and the intermediate-range repulsive interaction decreases with increasing salt concentration up to a certain concentration value but after that remains unchanged. However, for the monovalent ion (Na+), repulsive interaction decreases gradually up to 1 M salt concentration. Dynamic light scattering study shows that for all ions, diffusion coefficient of BSA decreases with increasing salt concentration and then nearly saturates.

In this report, the solubilization behaviour of a hydrophobic drug Clozapine (CLZ) in micellar suspensions of pluronics having different hydrophilic lipophilic balance (HLB) ratios viz. P84, F127 and F108 in the absence and presence of bile salt sodium deoxycholate (SDC) has been studied. UV-Vis spectroscopy has been exploited to determine the solubilization capacity of the investigated micellar systems in terms of drug loading efficiency, average number of drug molecules solubilized per micelle (ns), partition coefficient (P) and standard free energy of solubilization (∆G°). The morphological and structural changes taking place in pluronics in different concentration regimes of SDC and with the addition of drug CLZ has been explored using dynamic light scattering (DLS) and small angle neutron scattering (SANS) measurements. The SANS results revealed that aggregation behaviour of pluronic-SDC mixed micelles gets improved in the presence of drug. The micropolarity measurements have been performed to shed light on the locus of solubilization of the drug in pure and mixed micellar systems. The compatibility between CLZ and drug carriers (pluronics and SDC) was confirmed using powder X-ray diffraction (PXRD) and Fourier transform infrared spectroscopy (FTIR) techniques. Among the investigated systems, P84-SDC mixed system was found to be highly efficient for CLZ loading. The long term stability data indicated that CLZ loaded P84-SDC mixed micellar formulation remained stable for 3months at room temperature. Further, it was revealed that the CLZ loaded P84-SDC mixed micelles are converted into CLZ loaded pure P84 micelles at 30-fold dilutions which remain stable up to 48-fold dilutions. The results from the present studies suggest that P84-SDC mixed micelles can serve as suitable delivery vehicles for hydrophobic drug CLZ.

We report on the aggregation behavior of the mixed systems composed of sodium oleate (NaOl) with various imidazolium based ionic liquids (ILs) using tensiometry, rheometry and small angle neutron scattering (SANS). The effect of alkyl chain in 1-alkyl-3-methylimidazolium chloride, ([Cnmim][Cl], where n = 4 to 10) showed that ILs with long chain length (~ C10) exhibit spontaneous transition of micelles into vesicles. The comparison in ILs with same alkyl chain (C8) but with different counterions viz. chloride [Cl−], tetrafluoroborate [BF4−] and hexafluorophosphate [PF6−] showed that IL with hydrophilic ion Cl− exerts micellar transition while hydrophobic PF6− showed no noticeable effect. However, an interesting finding in this paper is the unusual behavior of IL with moderately hydrophobic BF4− that transforms micelles into vesicles. Moreover, mixed micellar systems of NaOl and IL transform into vesicular solution when pH condition turns into acidic. Tensiometric measurements disclosed strong synergistic interactions between the oppositely charged ILs and NaOl. The information on the modification of micellar characteristics of NaOl/ILs mixed system is useful for industrial applications.

Sophorolipid (SL), a bio-derived surfactant is an excellent gelling agent for natural fibrous protein, silk fibroin (SF) leading to potential biomedical applications. Interaction of SF with SL has been shown to accelerate the formation of hydrogel with the rate being dependent on the form of SL used. Here, we examine the effect of pH on SL-SF interaction and gel formation by employing rheology, fluorescence spectroscopy, SANS and NMR. The results indicate that the size of SL assemblies decrease as pH increases from acidic to alkaline and significantly impacts the association of SL and SF. The association of SF and SL is mainly via hydrophobic interactions, with the SL molecules forming bead like structures along the SF chain. The increased charge on the acidic form of SL at higher pH results in greater repulsion between acidic SL molecules, which are bound to the hydrophobic sites of SF, leading to rapid chain unfolding and subsequent gelation.

Pluronics are used in industry as solubilizing agents for a variety of lipophilic compounds. The influence of different lipophiles on aggregation characteristics of Pluronics quite expectedly remained a subject of fundamental interest for the last few decades. In this manuscript, we show that solubilization of tea tree essential oil (TTO) brings about spherical-to-worm like micelles-to-vesicular structural transitions in aqueous solutions of Pluronic P123. TTO exhibits broad-spectrum antimicrobial properties and have therapeutic potential for wide range of diseases ranging from common wounds to different forms of cancers. Its solubilization in Pluronic solutions was carried out by subjecting the aqueous TTO-Pluronic systems into heat cycling through their phase separation temperature. We suggest that accelerated dynamics of micellar restructuring process in Pluronic P123 solutions at high temperature is responsible for solubilization of TTO upon heat cycling. Such instances of oil solubilization upon heat treatment and subsequent systematic micellar structural transitions are first of its kind in aqueous systems of nonionic surfactants. TTO solubilized Pluronic solutions exhibit antimicrobial property and cytotoxicity to breast (MCF7) and lung (A549) cancer cells, which suggest that therapeutic activity of TTO is not destroyed upon heating induced micellar solubilization.

This work aims to optimize the aqueous solution behavior in mixed system of polyethylene oxide-block-polypropylene oxide-block-polyethylene oxide (PEO-PPO-PEO). Two copolymers viz., P123 and F127 (with same size of hydrophobic PPO block and 30 % and 70 % hydrophilic PEO end blocks, respectively) were used and the changes in size self-assembled mixed micelles were examined in the presence of small amount of four very hydrophobic copolymers viz., L61, L81, L101, and L121 (each with 10 % PEO but varying PPO molecular weight). The cloud point (CP) show the changes in the phase behavior of the examined systems while the relative viscosity (ηrel) pointed out marked changes in the flow behaviour. The micellar characteristics (size, shape, aggregation number) determined by dynamic light scattering (DLS) and small-angle neutron scattering (SANS) depict the plausible morphological transition expressed as apparent hydrodynamic diameter (Dh), hard sphere radius (Rhs), aggregation number (Nagg) at different temperatures. Such modulations in the mixed Pluronics® systems are further examined for the solubilization of hydrophobic anticancer drug curcumin (Cur). The enhanced Cur solubility is well-established from the distinctive peak intensities as observed from UV–Visible (UV–vis) and Fourier Transform Infrared (FT-IR) spectral profile which validated the interaction of Cur with the examined copolymeric systems.

The present study was undertaken to unveil the self-assembly of a polyoxyethylene alkyl ether carboxylic acids based nonionic amphiphile known as Akypo® RO90 VG (hereafter written as Akypo) in aqueous medium using cloud point (CP), solution viscosity, dynamic light scattering (DLS), small-angle neutron scattering (SANS) measurements. Surfactants belonging to Akypo family have an average formula CxEOyCH2COOH (i = 8–18, j = 2.5–10) [1] . The surfactant micellizes in aqueous media analogous to conventional surfactants but with some dissimilarity. The influence of external stimuli viz. temperature, pH and electrolyte has been examined to assess the response on the microstructural changes in micelles. SANS experiments provided the exact size and shape of micelles; the micellar growth proposed by high solution viscosity and hydrodynamic diameter (Dh) of micelles from DLS and further reinforced by SANS data. This further divulges that increase of temperature and addition of electrolyte persuade the ellipsoidal to worm-like micellar transition. Change of pH towards an alkaline medium favors the transformation of ellipsoidal micelles into spherical ones which can be correlated with deprotonation of carboxylic acid groups that results in increased solubility of Akypo. The current study authorizes how the size of Akypo micelles can effortlessly be amended in the presence of external stimuli to the desired extent.

Considerable attention is clutched by aqueous metal ion rechargeable batteries owing to their high energy density, low cost, nonflammability, and much environmental benignity with a safer alternative. However, effective manipulation in the electrolyte, such as the addition of polymers in an aqueous electrolyte system, is ongoing to suppress the leakage and water splitting behavior to expand its utility as improved energy storage devices. Here, the structural self-assembly of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO53-PPO34-PEO53, Mol. Wt. = 6600 gm mol−1) block copolymer, Pluronic® F77 in aqueous solutions were investigated, and the effect of ionic additives especially cation influence onto micellar size by small-angle neutron scattering (SANS), dynamic light scattering (DLS) and proton nuclear magnetic resonance (1H NMR) were systematically studied. The micellar structural parameters obtained from SANS data analysis with core–shell model noticed a decrease in core radius, aggregation number, and hard-sphere radius of micelles proved overall demicellization phenomena when salts were added. The results were supported by DLS study where a similar trend in radial decrement and NMR peak shifting supported the SANS results. Moreover, elementary electrochemical investigations such as ionic conductivity and transport number were also carried out for the applications into aqueous rechargeable batteries and supercapacitors.

Aqueous solubility and stability of curcumin could be ameliorated through its encapculation within the micellar and vesicular assemblies. This could protect curcumin from the attack of inactivating enzymes in the biological fluid and improve its medicinal and therapeutic effects. In our efforts to design surfactant based organized assemblies as drug carrier, herein, we had reported the formation of catanionic vesicles to encapsulate curcumin. The catanionic vesicles are formed through synergistic interaction between sodium butyrate (NaBut) and ester functionalized morpholinium and imidazolium-based surface active ionic liquids (SAILs). Fluorescence resonance energy transfer (FRET) and small-angle neutron scattering (SANS) were among the methods that were used to confirm the presence of curcumin within the bilayer of the vesicles. Loading capacity and stability of the curcumin within the micelles and vesicles were investigated. Results concludes that vesicles because of their higher hydrophobic character improve the encapsulation and inhibit the degradation of curcumin. The curcumin loaded catanionic vesicles were found effective against Gram-positive and Gram-negative bacteria and must be exploited for clinical applications. The newly fabricated system would pave the way for the stabilization of the curcumin and increased its application potential in the field of biotechnology and sustained drug delivery.

Spanlastics (viscoelastic vesicles) have evolved from nonionic surfactant vesicles, and are composed of vesicle builder (VB) and edge activator (EA). EA engages with the bilayer of vesicles and modulates its fluidity, elasticity and integrity. In this study, we hypothesized to modulate the microstructural characteristics of Span 80 (sorbitan monooleate) vesicles using Tween 80 (a hydrophilic micelle forming non-ionic surfactant, polyoxyethylated Span 80) as EA. The experiments were designed to investigate the effect of EA-VB ratio (2:1, 1:1 and 1:2) and total surfactant concentration (0.5%, 1.0%, 2.0%, 5.0% and 10% v/v) upon formulation attributes. Formulations were prepared using injection method and structural transitions were studied using dynamic light scattering (DLS), small angle neutron scattering (SANS) and electron microscopy. Scattering results show that large vesicles were formed as (a) proportion of EA became low and, (b) total surfactant concentration increased from 0.5% to 10%. At a fixed EA-VB ratio (2:1), profound microstructural changes were noticed while we shifted towards higher surfactant concentration. Here, mixed micelle-rich aggregates (0.5%) transformed to a vesicle-micelle mixture along with an intervening phase dominated by ellipsoidal micelles. These structures could be verified from the electron microscopic data and changes in the viscosity of samples during application of controlled shear. Altogether, we show that morphology of vesicle and fluidity of its bilayer can be tuned through a careful optimization of EA concentration.

Optimal design of Beta zeolite membrane of a three-dimensional 12-ring interconnected channel system can be vital for environmentally sustainable industrial separation application. A faster route of crystal growth from colloidal solution resulted to formation of poly (nanocrystalline) zeolite Beta membrane. The present SANS study probed the underlying functional diversity of core-shell precursor nanoparticle depending on form and structure factor towards the crystal growth for Beta membrane formation. The data clearly distinguished nanoscale structural arrangements of the synthesis solution before the hydrothermal heat treatment, during the induction and nucleation periods. Initially, shells consisting of organic template, reactive Al species and other dissolved ions surrounded the colloidal silica nanoparticles. Some of the silica cores sizes reduced while the shell thicknesses increased resulting to a heterogeneous colloidal solution system consisting of particles of different core-shell dimensions. The evolution of extra-small core and extra-large shell in the heterogeneous system may be nucleating particles as confirmed by XRD pattern corresponding of zeolite Beta. Deposition of such nucleating particles over the support might led to the formation of Beta zeolite membrane. The SANS profile of the solutions further showed that the nucleating particles were more readily deposited over the zeolite-seeded support than the non-seeded support.

Importance of pluronic P85 as carrier for drugs arises due to its ability to sensitize cell membranes for delivery of drugs across multi drug resistant cancer cells and blood brain barrier. It is thus necessary to understand how lipophilic drugs and phytochemicals influence its self-assembly characteristics and how the therapeutic properties of these lipophiles are modulated upon encapsulation in P85 micelles. We have investigated solubilization characteristics of Lavender essential oil (LO) in P85 and P85-P123 micellar systems and studied the associated structural and therapeutic properties by DLS, SANS, viscosity, ITC, antimicrobial and in vitro cancer cell viability studies. We observed that LO induces micellar structural transitions in aqueous P85 and P85-P123 systems leading to the formations of worm like micelles and vesicles. LO solubilized systems exhibit anticancer and antimicrobial properties, and show existence of double cloud points namely, upper and lower cloud points (UCP & LCP). A spherical-to-elliptical micellar structural transition is observed in these LO solubilized systems upon cooling down to LCP, which is unusual and not reported hitherto in aqueous pluronic systems. The observed results show how essential oils can influence the self-assembly characteristics of P85 based micellar systems and how their therapeutic properties are manifested under micellar encapsulation.

Surfactant vesicles have elicited the attention because of their non-toxic nature, ease of preparation, low cost programmable drug delivery vehicle and soft templates for the organized nano-assemblies. To unleash their potential as the new age drug carrier, herein we have designed catanionic vesicles formed through synergistic interactions between the hydrotropic drug diclofenac sodium (DS) and cationic gemini surfactants (GS) with varying alkyl chain lengths i.e. hexamethylene 1,6-bis (tetradecyl dimethyl ammonium bromide); and hexamethylene 1,6-bis (hexadecyl dimethyl ammonium bromide). The prepared catanionic vesicles were then used as the soft templates to synthesize hollow silica nano spheres with 62 nm size and 0.86 cm3/g pore volume to accommodate the anti-cancer drug imatinib mesylate. Results of encapsulation and release demonstrate that the studied system could potentially serve as a stable nano-delivery system for delivering the hydrophobic drugs in the future.